Crystalline-Si photovoltaic devices with ZnO nanowires

The growth of ZnO nanowires (NWs) on a zinc oxide (ZnO)/textured crystalline-Si (c-Si) photovoltaic device via the hydrothermal method is investigated. The average length and diameter of the ZnO NWs are around 0.65 μm and 70-100 nm, respectively. Experimental results indicate that a ZnO/textured c-Si photovoltaic device with ZnO NWs has the lowest reflectance among the tested substrates, especially in the range of ultraviolet (UV) and green light (350 nm to 590 nm). Compared to SiNx/textured c-Si and ZnO/textured c-Si photovoltaic devices, the proposed device exhibits photovoltaic conversion efficiency improvements of around 7% and 6.3%, respectively. After encapsulation, the ZnO NWs/ZnO/textured c-Si photovoltaic device has the lowest drop in conversion efficiency. Furthermore, a small NW diameter increases light absorption.